Rituximab therapy in connective tissue disease associated interstitial lung disease - a retrospective single centre observational study

Abstract

Introduction: Connective tissue disease associated interstitial lung disease (CTD-ILD) is a challenging clinical entity. Rituximab (RTX) is a chimeric monoclonal antibody targeted to CD20+ B-cells, resulting in B-cell depletion and has been suggested as a potential therapeutic modality in progressive disease. Objectives: To investigate the therapeutic effects and safety of rituximab in patients with progressive CTD-ILD. Methods: A retrospective observational analysis was performed at WDGMC between January 2010 and December 2020. A total of 19 patients with CTD-ILD were treated with RTX and various combinations of immunomodulatory therapy. The effects of RTX were investigated with serial pulmonary function testing (PFT), high resolution computed tomography (HRCT) of the chest, and the WHO functional class assessment (FC). Results: At an average of 24-month follow up from baseline, the mean change in forced vital capacity (FVC) was not significantly different from baseline (0.01L, 95% CI -0.13 to 0.14L) (p=0.91). At an average of 24-month follow up, 17 follow up HRCTs were available of which 13 showed disease stability, 3 indicated progression and 1 indicated improvement. At an average of 24-months follow up, FC remained stable compared to baseline (p=0.083). No serious adverse drug reactions or mortalities occurred. Conclusion: Rituximab is a potential therapeutic option in patients with progressive CTD-ILD and appears to result in stability in FVC, HRCT findings and FC over a 24 month period.